This project has worked in two general areas over the last year, new imaging techniques and functional MR imaging of the human heart. New imaging techniques include Hall effect imaging and electroaoucstic imaging. Both reveal information about the electrical properties of tissue, such as ion and macromolecule mobility. Hall effect 3D tomography has been demonstrated in phantoms at 1.5mm resolution. Electroacoustic signals from ex vivo tissue samples were collected. Currently our focus in this area is quantification and correlation between the electroacoustic measurements and physiological parameters. Both techniques require ultrasound transmitter/sensors that have very low electromagnetic noise. We design and construct laser based ultrasound transducers for this purpose. In cardiac magnetic resonance imaging it is of great significance to track the motion of the myocardium. We developed a stimulated-echo based phase tagging method capable of high resolution motion measurements. Recent improvements of this method made possible single breathhold human imaging. Automatic data processing gives contractile strain maps of the heart seconds after the image collection. These maps show the degree of muscle contraction in the heart at 2.5 mm resolution, an important piece of information in diagnosing heart diseases. - Hall Effect Imaging Electroacoustic Fiber-optic Sensors Ultrasound Displacement Mapping - Human Subjects